Auger



J. S'TIEN wean Filed Aug. 23, 1924 Fl l3 .1 F I E311 FIEJIIII.

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. 3 v FIEJX. FIEX. FIG-XL- w/r/visses Patented Aug. 25, 1925.

UNITED STATES PATENT OFFICE.

JACOB STIEN, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR 0F IEOQRTY-FIVE ONE- HUNDREDTHS T0 BENJAMIN E. THOMAS, OF PITTSBURGH, PENNSYLVANIA.

AUGER.

' Application filed August 23, 1924. Serial No. 733,700.

To all whom it may concern:

Be it known that I, JACOB STIEN, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful Improvements in Angers, of which improvements the following is a specification.

My invention relates to improvements in angers, and while not limited to angers of any particular size or for any particular service, it finds practical application in angers used in coal mines, for boring holes in the breast of coal to receive the charge for blasting. In this particular application I shall show and describe it.

My improvement consists in an anger provided with removable bits of particular character and shape, having the recognized advantage of a removable and replaceable bit, the bit in its shape and arrangement cooperating with the shape of the body of the auger, to afford an instrument peculiarly adapted to the conditions of service.

My invention is illustrated in the accompanying drawings in which Fig. I is a view in perspective of the cutting end of the anger of my invention; Fig. II is a view in side elevation of the shank of the auger alone, lacking the bit. In Fig. II the auger is viewed from a position at right angles to that of Fig. I Fig. III is a view in end elevation of the shank of the auger. Fig. IV is a view in side elevation of one of the bits. Fig. V is a view of the bit in plan from above. Fig. VI is a view in crosssection of the bit, on the plane indicated at VIVI, Fig. IV. Figs. VII, VIII, IX, X, and XI are views corresponding to Figs. II, III, IV, V, and VI, and illustrating an alternative form of attachment of bit to auger shank.

Referring first to Figs. I, II, and III of the drawings, the auger will be seen to be a screw auger and to include a shank 1 and bits 2. The shank is formed as the shank of a screw auger ordinarily is formed, of a bar of iron forged thin and flat and then twisted on its central longitudinal axis, constituting a spirally flanged shank. At its bit-receiving end the shank is bifurcated as at 3, 3, and is suitably shaped to receive and carry the bits 2 removably secured to it. These furcations, as is best shown in Fig. I, do not conform to the twist of the shank,

but deviate from that twist and extend with their forward faces-that is to say, faces; a,

Fig. III (the direction of rotation being anti-clockwise) approaching 1 more closely to parallelism with the axis of the shank. Each of these two forward faces a of the bifurcations at the end of the stem is faced with a bit.

Comparing Figs. I, IV, and V, it will be observed of the bit that it is formed of a short bar of metal, and that it too is twisted, and it is so twisted that when applied, its forward face conforms with greater or less accuracy to the extended surface of twist of the shank. This is accomplished by twisting the bar on an approximately longitudinal axis, but this longitudinal axis with respect to which the twist is developed, is a longitudinal axis which is exterior of the bar itself, and is spaced with respect to the bar at the distance that the axis of the shank is spaced, when the bit is in place. It will be apparent then on considering Fig. I, that the bifurcation 3 so far departs from the continuity of the twist of the shank 1, and the bit 2 itself is so particularly twisted, that when the bit has been applied and is in place, the forward face of the bit conforms, with'a sufficient degree of approximation to be useful, to the twisted surface of the shank, and presents to the work a spiral surface, springing from the base of the furcation, and continuous with the spiral surface of the shank. It is of course recognized that the twist of the shank is useful in the operation of the bit, in removing from the hole the material which is cut by the bit. This conformation of the face of the bit, therefore, to the twisted surface of the shank of the bit makes for more eflicient service.

Figs. I, IV, and VI indicate one means of attachment of the bit to the shank. The bifurcations of the shank are diminished at the tips to form studs 4, wedge-shaped in cross-section and shouldered at the base. The bit is provided with backwardly turned lips 5 which, as best shown in Fig. VI, afford a correspondingly dove-tailed recess by which the bit may be slipped to place and secured upon the studs t. The shoulders afford the necessary abutment to hold the bits secure totheir work. Cotter pins 7 may be provided to afford greater security.

The alternative means of securing the bits to place shownin Figs. VII, IX, and XI are the bolts 6, extending through the bits 2 and through the bifurcations formed on the end of the shank of the auger. Nuts may of course be applied to make these bolts effective.

It will be observed that in both cases the bit is secured to the shank at a. point mid way the length of the bit. It has been explained that the bit when in place faces the bifurcations formed on the end of the shank that the forward face of the bit when in position conforms to the twist of the shank. Referring again to Fig. I, it will be observed that the bit when in place not merely overlies the face of the furcation 3, but that it extends substantially to the base of the furcation, and that its forward face 7) merges in the twisted surface 0 of the shank of the bit. This merging of the bit surface in the shank surface is facilitated by the fact that the bit is tapered to opposite edges.

The bit of course is reversible and either of its opposite edges may be presented to the Work. It is easily fashioned and easily shaped, and of course easily replaceable. It has advantage over a replaceable double bit in this additional respect, that the breaking of the cutting edge on one side does not involve the laying aside of a good cutting edge on the other side.

I claim as my invention:

A screw augerincluding a shank with spiral flange terminally bifurcated, the work-facing surfaces of the furcations diverging from the spiral to which the flange of the shank otherwise is formed, and bits borne by said furcations, each bit having a chisel edge and being detachably secured to the furcations, so that the cutting edge lies entirely within the space which is a continuation of the curvature of the underside of the flange.

In testimony whereof I have hereunto set my hand.

JACOB STIEN. 

